Oxygen isotope systematics of ordinary chondrite chondrules: insights into the inner solar system planetary reservoir

Chondrules are fundamental objects from which important insights in the conditions of the solar protoplanetary disk can be inferred. In this regard, oxygen isotope composition of chondrules have played a key role tracking the physicochemical environment under which their formation occurred. It has been proposed that chondrite asteroids accreted specific chondrule groups or ‘chondrule populations’ in terms of oxygen isotopes but this hypothesis has never been statistically assessed. Systematic in situ measurements of oxygen isotope composition of chondrule olivine from ordinary chondrites (H, L, and LL groups) by SHRIMP-SI and a robust statistical evaluation allowed us to conclude for the first time that the different ordinary chondrite parent bodies sampled the same main population of chondrules in their accretion location. This population is characterised by a mean of Δ17O = 0.74 ± 0.10‰ (σ95%) with a variability of 0.53‰ (σ95%). Ordinary chondrite chondrules were then formed in the same gaseous oxygen isotope reservoir or region of the protoplanetary disk. This population is formed by chondrules with different chemical composition (Type I and Type II) indicating that their formation region was chemically differentiated and form a chemical continuum rather than two separated classes. Our results together with literature data lead us to propose an oxygen isotope gradient of the protoplanetary disk ambient gas under which these and other astrophysical objects (e.g. refractory inclusions) were formed, 16O-richer closer to the Sun and 16O-poorer at longer radial distances. Ultimately, we suggest a change in the paradigm related to the oxygen isotope reservoirs of the solar system, particularly the so-called planetary reservoir. It is proposed that the gaseous oxygen isotope planetary reservoir is a discrete reservoir enriched in SiOgas molecules and other rock-forming elements present since the earliest stages of the solar system evolution possibly reflecting the average oxygen isotope composition of the primordial dust of the solar nebula. The mean composition of the planetary reservoir is δ18O = 4.64 ± 0.15‰ (σ95%) and δ17O = 3.03 ± 0.10‰ (σ95%), with variabilities of 0.97‰ and 0.52‰ (σ95%), respectively

Revisión de la sección Brevispicae del género Sloanea (Elaeocarpaceae) en Bolivia

A critical checklist and illustrated of the species of section Brevispicae of the genus Sloanea is presented for Bolivia, seven species are recognized (S. eichlerii, S. guianensis, S. obtusifolia, S. picapica, S. pubescens, S. spathulata and S. tuerckheimii). A key to separate species is presented and for each are provide comments on taxonomic affinities, material type, distribution, habitat, common names and uses.Se presenta un catálogo comentado e ilustrado de las especies de la sección Brevispicae del género Sloanea para Bolivia, se reconocen siete especies (S. eichlerii, S. guianensis, S. obtusifolia, S. picapica, S. pubescens, S. spathulata y S. tuerckheimii). Se presenta una clave para separar las especies y para cada una se proporcionan comentarios sobre afinidades taxonómicas, material tipo, distribución, hábitat, nombres comunes y usos

SLOANEA SUBGÉNERO QUADRISEPALA (ELAEOCARPACEAE) EN BOLIVIA

Se presenta una sinopsis del subgénero Quadrisepala del género Sloanea, para Bolivia, en la que reconocen once especies (Sloanea fendleriana, S. garckeana, S. gentryi, S. grandis, S. latifolia, S. laxiflora, S. porphyrocarpa, S. rojasiae, S. subsessilis, S. terniflora y S. uniflora), destacando que S. latifolia, S. porphyrocarpa y S. rojasiae son nuevos registros para la flora de Bolivia. Adicionalmente, se complementa la descripción original de S. subsessilis con la incorporación de caracteres del fruto y se proponen lectotipos para S. grandis y S. porphyrocarpa

Muscle Activation and Distribution during Four Test/Functional Tasks: A Comparison between Dry-Land and Aquatic Environments for Healthy Older and Young Adults

Background: The use of rehabilitation protocols carried out in water has been progressively increasing due to the favorable physical properties of the water. Electromyography allows one to register muscle activity even under water. Aim: To compare muscle activity between two groups (healthy young adults (HYA) and healthy older adults (HOA)) in two different environments (dry land and aquatic) using surface electromyography during the execution of four different test/functional movements. Methods: Analytical cross-sectional study. HYA and HOA carried out four functional tasks (Step Up and Down, Sit TO Stand test, Gait Initiation and Turns During Gait) in two different environments (dry land and aquatic). Absolute and relative muscle activation was compared between each group and between each environment. In addition, the stability of the measured was calculated through a test-retest (ICC 2:1). Results: Within the same environment there were significant differences between young and older adults in three of the four functional tasks. In contrast, in the gait initiation, hardly any significant differences were found between the two groups analysed, except for the soleus and the anterior tibial. Measurement stability ranged from good to excellent. Conclusions: Level of the musculature involvement presents an entirely different distribution when the test/functional task is performed on dry land or in water. There are differences both in the relative activation of the musculature and in the distribution of the partition of the muscles comparing older and young adults within the same environment

Estudio de la propagacion vegetativa natural y ganancia de peso en tulipanes plantados en Mulchen VIII region

Resumen (Spanish, English)41 p.El Tulipán (Tulipa sp.), planta ampliamente cultivada en Holanda, fue estudiada en la localidad de Mulchén (73° 42' latitud Sur y 72° 20' longitud oeste) durante julio a diciembre de 1995 con el propósito de analizar su tasa de propagación vegetativa natural de bulbos florales y la ganancia de peso de bulbillos en la VIII Región de Chile. Se utilizaron bulbos de cuatro cultivares importados desde Nueva Zelanda (Lily Schier (LS), Klara Park (KP), Pandion (PA) y Queen of the Night (QN). Se trabajó con tres calibres diferentes (perímetros menor a 6 cm, 6 a 8 cm, y superior a 8 cm) de bulbos que tenían una temporada de cultivo en Chile y de bulbos recién llegados a Chile (perímetro superior a 8 cm). Se realizaron mediciones de peso, diámetro y número de bulbos antes de la plantación y a la cosecha. Como conclusión se obtuvo que a mayor perímetro de bulbos florales mayor es la tasa de propagación (número de bulbos y bulbillos producidos a partir de un bulbo floral) siendo la proporción de bulbos florales y bulbillos de aproximadamente 50%. Por otra parte no hubo una tendencia clara en la ganancia de peso entre los cuatro cultivares pero fue superior a la máxima señalada en literatura. Además se encontró una correlación inversamente proporcional entre la ganancia de peso y el número total de bulbos y bulbillos producidos durante el proceso de engorda

New Circumspection of the Genus \u3ci\u3eGamochaeta\u3c/i\u3e (Asteraceae, Gnaphalieae) Inferred From Nuclear and Plastid DNA Sequences

Gamochaeta (tribe Gnaphalieae, Asteraceae) is composed of ca. 60 species primarily distributed in tropical and subtropical America. Within the tribe Gnaphalieae, the genus is characterized by capitula arranged in spikes or head-like clusters, few hermaphroditic central florets, truncate style branches with apical sweeping trichomes, pappus bristles connate at the base into a ring falling as a unit, and achenes with globose twin trichomes. Previous molecular phylogenetic studies have suggested the paraphyly of the genus, but have not provided a basis for redefining generic limits due to incomplete taxon sampling. To address this problem, DNA sequences from the plastid (trnL-F) and nuclear (ETS and ITS) genomes were analyzed from a broad taxon sample representing the full range of morphological variation known in the genus. Our results affirm that Gamochaeta is paraphyletic as presently circumscribed. Two clades can be recognized: one clade that includes the majority of the species currently assigned to Gamochaeta and a second clade that includes Gamochaetopsis, Stuckertiella and seven species of Gamochaeta. We present here a new circumscription of Gamochaeta, including two new combinations, Gamochaeta alpina and Gamochaeta peregrina, and the resurrection of Gamochaeta capitata. Our results also show Omalotheca supina, O. norvegica and O. sylvatica, which were placed by some authors in Gamochaeta or in Gnaphalium, form a monophyletic group distantly related to both genera

New circumscription of the genus <i>Gamochaeta</i> (Asteraceae, Gnaphalieae) inferred from nuclear and plastid DNA sequences

Gamochaeta (tribe Gnaphalieae, Asteraceae) is composed of ca. 60 species primarily distributed in tropical and subtropical America. Within the tribe Gnaphalieae, the genus is characterized by capitula arranged in spikes or head-like clusters, few hermaphroditic central florets, truncate style branches with apical sweeping trichomes, pappus bristles connate at the base into a ring falling as a unit, and achenes with globose twin trichomes. Previous molecular phylogenetic studies have suggested the paraphyly of the genus, but have not provided a basis for redefining generic limits due to incomplete taxon sampling. To address this problem, DNA sequences from the plastid (trnL-F) and nuclear (ETS and ITS) genomes were analyzed from a broad taxon sample representing the full range of morphological variation known in the genus. Our results affirm that Gamochaeta is paraphyletic as presently circumscribed. Two clades can be recognized: one clade that includes the majority of the species currently assigned to Gamochaeta and a second clade that includes Gamochaetopsis, Stuckertiella and seven species of Gamochaeta. We present here a new circumscription of Gamochaeta, including two new combinations, Gamochaeta alpina and Gamochaeta peregrina, and the resurrection of Gamochaeta capitata. Our results also show Omalotheca supina, O. norvegica and O. sylvatica, which were placed by some authors in Gamochaeta or in Gnaphalium, form a monophyletic group distantly related to both genera.Facultad de Ciencias Agrarias y Forestale

Internacionalización de las prácticas de laboratorio en las asignaturas del área de Electromagnetismo del grado de Ingeniería Electrónica

En esta memoria se describen los resultados del proyecto num 122, "Internacionalización de las prácticas de laboratorio en las asignaturas del área de Electromagnetismo del grado de Ingeniería Electrónica". Se han realizado más de veinte vídeos divulgativos en ingles sobre las técnicas experimentales que se estudian en las asignaturas del Área de Electromagnetismo de la Ingeniería Electrónica de Comunicaciones. Estos vídeos se han cargado en un canal de Youtube, al que se puede acceder desde la página web www.ucm.es/elec

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks